[Are monozygous twins and twin-specific abnormalities more prevalent following extracorporeal fertilization? A comment on studies of the Gynecologic Clinic of the Erlangen-Nürnberg University].

IVF was performed in the Department of Gynecology and Obstetrics, University of Erlangen-Nürnberg, and monozygotic twins were established in one case, but were indicated in two more cases. In further two cases one sexlike twin had died from caudal regression. This malformation complex, which has been noted very occasionally in monozygotic twins, is considered to be related to the twinning process. The question is raised, as to whether after IVF monozygotic twins are expected more frequently. Furthermore the importance of this question is discussed with reference to recent observations in twin research.